Dyer, who was previously No 2, had been in caretaker charge following the departure of Angelo Alessio from Rugby Park a fortnight ago.
He told the club website: "I care deeply about this fantastic football club and it is a privilege to be named manager until the end of the season.
“I believe we have a good group of players at the club and, with a few additions during the transfer window, I’m convinced we can rejuvenate our season and re-establish the identity the club has built over the past few years.”